Answer:
70 because it is subtracted 121 by 51 to give u 70 use m
C is the answer.. B and D don't have anything to do with speed
Answer:
90 is 50% of 180
Explanation:
Just multiply 80 by 2 for 50%
Answer:
The mass of glucose that contains a million
carbon atoms is
.
Explanation:
Number of carbon atoms = ![1.0\times 10^6](https://tex.z-dn.net/?f=1.0%5Ctimes%2010%5E6%20)
1 molecule of glucose has 6 carbon atoms, then
will be in N molecules of glucose:
molecules of glucose
1 mole = ![N_A=6.022\times 10^{23} molecules](https://tex.z-dn.net/?f=N_A%3D6.022%5Ctimes%2010%5E%7B23%7D%20molecules)
Moles of glucose = n
![N=n\times N_A](https://tex.z-dn.net/?f=N%3Dn%5Ctimes%20N_A)
![n=\frac{N}{N_A}=\frac{\frac{1.0\times 10^6}{6}}{6.022\times 10^{23}}](https://tex.z-dn.net/?f=n%3D%5Cfrac%7BN%7D%7BN_A%7D%3D%5Cfrac%7B%5Cfrac%7B1.0%5Ctimes%2010%5E6%7D%7B6%7D%7D%7B6.022%5Ctimes%2010%5E%7B23%7D%7D)
![n=2.768\times 10^{-19} moles](https://tex.z-dn.net/?f=n%3D2.768%5Ctimes%2010%5E%7B-19%7D%20moles)
Mass of
moles of glucose;
![2.768\times 10^{-19} mol\times 180=4.9817\times 10^{-17} g\approx 4.98\times 10^{-17} g](https://tex.z-dn.net/?f=2.768%5Ctimes%2010%5E%7B-19%7D%20mol%5Ctimes%20180%3D4.9817%5Ctimes%2010%5E%7B-17%7D%20g%5Capprox%204.98%5Ctimes%2010%5E%7B-17%7D%20g)
which statement is true of phenolphthalien?
a. it can be used in combustion reactions.
b. it is colorless in the presence of an acid and pink in the presence of a base.
<u>c. it gives you the exact pH of a solution. </u>
d. it is colorless in the presence of a base and pink in the presence of an acid. e. it is called a decomposition indicator.